Vaccine

Abstract

The invention provides an attenuated rotavirus population comprising a single variant or substantially a single variant which is defined by a nucleotide sequence encoding at least one of the major viral proteins designated as VP4 and VP7. The invention particularly provides a rotavirus population designated as P43. The invention further provides a novel formulation for a rotavirus vaccine which is in the form of a quick dissolving tablet for immediate dissolution when placed on the tongue.

1 . A method of producing a purified human rotavirus population comprising a substantially single variant, the method comprising: 
 passaging a rotavirus preparation on a suitable cell line;    selecting a homogeneous culture using at least one of: 
 limit dilution; and  
 individual plaque isolation; and  
   identifying a substantially single variant by sequencing at least a portion of one or both of a VP4 and a VP7 gene sequence.    
     
     
         2 . The method of  claim 1 , wherein the rotavirus preparation is derived from a human rotavirus infection.  
     
     
         3 . The method of  claim 1 , comprising passaging the rotavirus preparation on cells selected from: AGMK cells and VERO cells.  
     
     
         4 . The method of  claim 2 , comprising passaging the rotavirus preparation on VERO cells.  
     
     
         5 . The method of  claim 1 , comprising selecting a homogeneous culture by limit dilution.  
     
     
         6 . The method of  claim 1 , comprising identifying a substantially single variant encoding a VP4 protein comprising at least one of a phenylalanine (Phe) at position 167, a glutamic acid (Glu) at position 263, and an arginine (Arg) at position 268.  
     
     
         7 . The method of  claim 6 , comprising identifying a substantially single variant encoding a VP4 protein comprising a phenylalanine (Phe) at position 167, a glutamic acid (Glu) at position 263, and an arginine (Arg) at position 268.  
     
     
         8 . The method of  claim 6 , comprising identifying a substantially single variant comprising a nucleotide sequence encoding VP4 comprising at least one of: an adenine base (A) at position 788; an adenine base (A) at position 802; and a thymine base (T) at position 501.  
     
     
         9 . The method of  claim 8 , comprising identifying a substantially single variant comprising a nucleotide sequence encoding VP4 comprising an adenine base (A) at position 788; an adenine base (A) at position 802; and a thymine base (T) at position 501.  
     
     
         10 . The method of  claim 1 , comprising identifying a substantially single variant encoding a VP7 protein comprising at least one of: a methionine (Met) at position 202, and an isoleucine (Ile) at position 299.  
     
     
         11 . The method of  claim 10 , comprising identifying a substantially single variant encoding a VP7 protein comprising a methionine (Met) at position 202, and an isoleucine (Ile) at position 299.  
     
     
         12 . The method of  claim 10 , comprising identifying a substantially single variant comprising a nucleotide sequence encoding VP7 comprising at least one of: a thymine (T) at position 605; an adenine (A) at position 897; and a guanine (G) at position 897.  
     
     
         13 . The method of  claim 12 , comprising identifying a substantially single variant comprising a nucleotide sequence encoding VP7 comprising a thymine (T) at position 605; an adenine (A) at position 897; and a guanine (G) at position 897.  
     
     
         14 . The method of  claim 1 , comprising selecting a homogenous culture with the characteristics of rotavirus strain 89-12 or a derivative thereof.  
     
     
         15 . The method of  claim 1 , wherein the homogenous culture comprises a single variant that replicates and is excreted by humans.  
     
     
         16 . The method of  claim 1 , further comprising treating the preparation with ether to remove adventitious ether-sensitive contaminating agents.  
     
     
         17 . A purified human rotavirus population comprising a substantially single variant produced by the method of  claim 1 .  
     
     
         18 . An immunogenic composition comprising the purified human rotavirus population of  claim 17  in admixture with an antacid and a viscous agent.